How do I access schedule B of form 1040 to subtract Nominee Distribution of interest reported on schedule k-1 that is overstated per irs instructions?

Here's how to split the 1099Int for Nominee Interest. Enter a 1099-Int under
Federal Taxes tab
Wages & Income
Interest and Dividends
Interest on 1099-INT - Click the Start or Update button

Whoever's ssn is on the 1099 enters the whole amount on their return. Then after you enter it, on the next page it will ask
Tell us if any of these uncommon situations Apply and pick the first one, We need to adjust the taxable amount.

Then on the next page fill in the amount as a POSITIVE number and pick the first Reason "I received all or part of this interest for someone else".

Then on the other person's return you enter it as a 1099Int and put their amount in box 1.